teeple



OF W'ILZMINGTON, DELAWAPE, ASSIGNSR T0 E, I. DU FONT DE OLIVER J. TEEPLE, as,

NET IO'URS AND COMPANY, WILMINGTON, DELAW'AELE, A CORPORATION OF HELA- PRGCE SQ 0F PEGDUCING- PROELLENT PQEVBER.

No Drawing.

To (.112 whom. it may concern:

Be it known that l, ()mven J. Tnernn, Jr, of Wilmiugtgm, in the county of New Castle, and. in the State of Delaware, have invented a certain new and useful Improvement in Processes of Producing- Propelleut Powder, and do hereby declare that the following is a full, clear, and exact description thereof.

My invention. relates to an improvement in processes of making propellent powders, but more particularly progressive powders, that is to say powders provided with coatings designed to retard the combustion, so as to provide a lower initial pressure.

The object of'my invention is to provide a process for producing, in an advantageous manner, propellent povders, and more particularly powders of the progressive type, which latter are designed for the purpose of providing a lower initim pressure Without decreasing the velocity of the projectile. More particularly, the object of my invention is to provide a process by means of which powder grains may have their surfaces in'ipregnated with compounds designed to retard the combustion in a very simple manner and in such a way as to at the same time preventthe powder grains from adhering together. A further object of my invention is to avoid the use of dangerous and inflan'imalole solvents in the coating process so as to thereby avoid loss and the ranger due to the escape of the solvent vapors.

While my invention is capable of being carried out in many different Ways, for the purpose of illustration, I shall describe only one Way in which my invention may he carried out. By way of example my process may be carried out as follows:

A quantity of a nitrocellulose or gelatinized smokeless powder in the form of grains is introduced intc the revolving drum provided with ports for the introduction and escape of steam. A quantity of a nitrohydroearhon, as for example, dinitrotoluene,

which can exert a solvent action upon the grain is now introduced into the drum in the form of a powder. The drum is now revolved for a short interval of time until the powder grains and the dinitrotoluene are Specification of Letters Eatent.

July .22,

Applicati r. f led July 29, 1916. Serial ll'o. 112,635.

being revolved. As a result the dinitrotoluene is melted so that the nitrocellulose g'ains become coated and impregnated at the surface with the melted dinitrotoluene.

'll' hen the coating and surface-iiupregnation has been completed the supply of steam is cut oil and the coated powder grains are permitted to cool. treatment the grains of nitrocelhilose will.

have been uniformly impregnated at the sur I face with the melted dinit-rotoluene, and that the powder grains do not adhere toone another during the procei This is an important difference over the treatment by means of hot air hitherto proposed, as by the latter method the action of the hot air causes the powder grams to adhere to one another, so that it becomes necessary to provide means for separating the g sins for that reason. in my process there is no tendency for the grams to adhere to one another at any tune.

This may he due to the presence or Water formed by the condensation. of the' It will. he found that by this I steam in small amounts or to other causes.

1. The process which comprises tumbling a gelatinized powder grain with a powdered material which is a solvent for the grain, and then melting the solvent during the continued tun'ihling operation with a hot aqueous vapor to impregnate the surface of the grain with the solvent. 7 I

2. The process which comprises tumhlin a gelatinized powder grain with a materia which is a solvent for the grain, and melting the solvent during the tumbling operation with a hot aqueous vapor to colloid the solvent With the material of the powder grain and impregnate the surface of the grain with the solvent.

3. The process which comprises tumbling a gelatinized powder grain with a powdered dinitrotoluene mixture, and melting the dinitrotoluene with steam during ghe turnblingoperation to colloid the solvent with the material of the powder grain, and impregnate the surface of the grain with the solvent material which can exert a solvent action on the. grain, and heating the powder and solvent during the tumbling operation to a temperature saiiicient to melt the solvent in the presence of water vapor to colloid the solvent with the surface material of the nitrocellulose grain, and thus impregnate the surface of the grain with the solvent.

5. The process which comprises applying; to agelatinized powder grain a powdered material whichcan exert a solvent action on the grain, and melting said material with a hot vapor to impregnate the surface of the grain with said material.

The process which comprises applying to a. gelatinized powder grain a-dinitrotoluene solvent, and melting the dinitrotoluene with steam to colloid the dinit-rotoluene With the material of the powder grain, and impregnate the surface of the grain With the dinitrotoluene.

7. The process which comprises applying; to a gelatinized powder grain a material which can exert a solvent action on the grain, and heating the powder and said ma terial to a temperature sufficient to melt the material in the presence of Water vapor to colloid the material with the surface material of the grain, and impregnate the surface of the grain with said material.

In testimony that I claim the foregoing I have hereunto set my hand.

OLIVER J. TEEPLE, Jn,

\Vitnesses W. W. R-IoHARns, i F. W. BRADWAY. 

